From 66dabbb65d673aef40dd17bf62c042be8f6d4a4b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 7 Mar 2023 15:34:10 +0100 Subject: mm: return an ERR_PTR from __filemap_get_folio Instead of returning NULL for all errors, distinguish between: - no entry found and not asked to allocated (-ENOENT) - failed to allocate memory (-ENOMEM) - would block (-EAGAIN) so that callers don't have to guess the error based on the passed in flags. Also pass through the error through the direct callers: filemap_get_folio, filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio. [hch@lst.de: fix null-pointer deref] Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004 Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Ryusuke Konishi [nilfs2] Cc: Andreas Gruenbacher Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- mm/truncate.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'mm/truncate.c') diff --git a/mm/truncate.c b/mm/truncate.c index 7b4ea4c4a46b..86de31ed4d32 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -375,7 +375,7 @@ void truncate_inode_pages_range(struct address_space *mapping, same_folio = (lstart >> PAGE_SHIFT) == (lend >> PAGE_SHIFT); folio = __filemap_get_folio(mapping, lstart >> PAGE_SHIFT, FGP_LOCK, 0); - if (folio) { + if (!IS_ERR(folio)) { same_folio = lend < folio_pos(folio) + folio_size(folio); if (!truncate_inode_partial_folio(folio, lstart, lend)) { start = folio->index + folio_nr_pages(folio); @@ -387,14 +387,15 @@ void truncate_inode_pages_range(struct address_space *mapping, folio = NULL; } - if (!same_folio) + if (!same_folio) { folio = __filemap_get_folio(mapping, lend >> PAGE_SHIFT, FGP_LOCK, 0); - if (folio) { - if (!truncate_inode_partial_folio(folio, lstart, lend)) - end = folio->index; - folio_unlock(folio); - folio_put(folio); + if (!IS_ERR(folio)) { + if (!truncate_inode_partial_folio(folio, lstart, lend)) + end = folio->index; + folio_unlock(folio); + folio_put(folio); + } } index = start; -- cgit